


Trying Something New

by cloud_dcst (greatcloudninja)



Category: Dr. STONE (Anime), Dr. STONE (Manga)
Genre: Alternate Universe - Modern Setting, Consensual Kink, Cuckolding, Discord: The Kingdom of Shipping (Dr. STONE), Established Relationship, Explicit Sexual Content, Feelings Realization, Friends With Benefits, Kink Exploration, Kink Negotiation, M/M, Mentions of Kohaku/Mozu, Mentions of Ooki Taiju/Ogawa Yuzuriha, Mentions of Stanley Snyder/Dr. Xeno, NaNoWriMo 2020, Personal Growth, Polyamory Negotiations, Praise Kink, Pre-Poly, Safe Sane and Consensual, Sex Toys, Size Kink, TheKingdomofShipping, Unrequited Crush, Verbal Humiliation
Language: English
Status: In-Progress
Published: 2020-11-15
Updated: 2020-12-13
Packaged: 2021-03-10 05:01:32
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 3
Words: 5,910
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/27578221
Author URL: https://archiveofourown.org/users/greatcloudninja/pseuds/cloud_dcst
Summary: “Well, I’m glad you two were able to be friends again! I know Senku always thought very highly of you.”“I wonder…” The cryptic response drew a head tilt from Chrome and a curious look. Tsukasa just chuckled and shook his head. “Oh, it’s nothing. Just… during those first two years, before you and he got together, we were more than just friends.”The words seemed to echo oddly in Chrome’s ears. What did that mean? What kind of relationship did Senku have with Tsukasa? But he’d said Chrome was his first real boyfriend…------------------------------------Chrome finds out Senku and Tsukasa were sex friends in college. It opens up a whole new world of kink to the sheltered country boy.His and Senku's relationship will never be the same.(Written for NaNoWriMo 2020)
Relationships: Chrome/Ishigami Senkuu, Chrome/Ishigami Senkuu/Shishiou Tsukasa, Chrome/Shishiou Tsukasa, Ishigami Senkuu/Shishiou Tsukasa
Comments: 27
Kudos: 37





	1. Chapter 1

**Author's Note:**

> I started writing this fic months ago with the intention of it being a one-shot, focusing strictly on the concept of Tsukasa cuckolding Chrome. But after not touching it for three months, I decided to revisit it and rework it into a multi-chapter fic for National Novel Writing Month!
> 
> Fic is unbeta-ed (as is the nature of NaNoWriMo fics) and I have no idea how often I'll update it, but the goal is to be finished with the fic by the end of the month.

Chrome stretched and sighed in relief as he felt his back crack. He leaned over and pressed a soft kiss to Senku’s forehead before tucking his feet into his slippers and shuffling out of the bedroom toward the kitchen. It was a Saturday morning and they had no urgent plans—meaning he had the perfect opportunity to surprise Senku with breakfast in bed.

It was the least he could do after his body gave out early last night and Senku had to finish with a vibrator.

The memory of last night’s events rankled at Chrome’s pride, as they always did. He’d tried supplements, but they left him feeling almost paranoid, strung out like he was on some sort of illicit substance. Homeopathic medicine didn’t help, either—not that he’d thought it would, but it had been a shot in the dark. No “aphrodisiac” foods could make him last longer or keep him going past his normal limits. It left Chrome feeling… inadequate, like he couldn’t measure up to what Senku needed. 

Despite the fact that they’d been together for over three years, Chrome still feared that his lack of performance in bed would be his downfall sooner or later. Senku never said anything about it, but sometimes after sex, he got a look on his face—like he was thinking about or remembering something, an almost nostalgic expression. Chrome knew Senku hadn’t been a virgin when they’d started dating; hell, for that matter, neither was he. Chrome had lost his virginity just after high school, his schoolboy crush on his neighbor’s older sister Ruri culminating in him punching his V-card after he graduated.

That relationship had lasted all of one year, while the two of them attended different universities, until Ruri had tearfully confessed that she’d met someone at her school and wanted to break up. It had been hard on Chrome, but Senku—his best friend, his lab partner and mentor and everything else two men could be together—had helped him through it… and helped him discover something about himself at the same time. A brief existential crisis and an all-night research session later, Chrome had found a new label for himself: _bisexual._

Senku, on the other hand, had long since explained that he was gay; but after Chrome’s revelation, he’d added another tag to Chrome’s mental reference file. _Demisexual,_ a form of asexuality where he didn’t become sexually attracted to someone without having a close emotional bond with them first. Prior to that emotional connection, sex was physically pleasurable, but nothing more than stress relief. He didn’t feel any different using a toy or his hand than he did being fucked by another person.

For Chrome, who’d grown up in a tiny rural fishing village near a mountain hot spring, where men married women and had kids and the generations rolled on just as reliably as the seasons, it was a whole new world. _Senku_ was a whole new world, and Chrome loved him. It was a feeling as simple as the sunrise, as strong as the tides breaking boulders into sand, and as complex as the delicate dance of planets and moons and asteroids and comets making their way around the sun. 

So for Chrome to not be able to satisfy Senku in every way… he felt like a disappointment. Like he wasn’t worthy of his partner and lover. Of course Senku would disagree, but it didn’t change the way Chrome felt inside. So, when he had opportunities to do things like this, he took advantage of them.

He was just putting the grilled mackerel on a plate when he heard the sound of bare feet on the wooden floor of the bedroom. Chrome hurried to get the rice scooped into a bowl and the miso soup ladled up, placing two servings of everything on a tray and carrying it into the bedroom. Senku’s eyes widened at the sight of the food Chrome was bringing in. “What’s all this about?” he asked.

“I wanted to do something special for you,” Chrome replied, smiling softly. “Breakfast in bed was the first thing I could think of.”

“Well, I’m not in bed anymore, but I guess I could be convinced to go back,” Senku drawled. “Let me just take care of something first.”

Nodding, Chrome stepped aside to let Senku pass. He set the tray on the bedside table and picked up one of the cups of tea, sipping on it idly as he waited for Senku to finish with his morning ablutions. The man returned a few minutes later and settled in next to Chrome with a grin. “So you made a traditional Japanese breakfast, hm? It smells amazing. You’ve really come a long way with your cooking.”

The praise made Chrome’s cheeks flush. “Well, I’ve had a great teacher. And it’s a lot easier to make good food when you have access to more ingredients than just fish and forage.”

“Ten billion percent true.” Senku picked up the miso soup and sipped at it, then used the chopsticks to break off a piece of mackerel. Between the two of them, they ate every bite of food, trading soft kisses between mouthfuls of rice and fish. “Thank you, Chrome. That was delicious.”

“Of course, Senku. I wanted to do something special for you.”

“You didn’t have to, you know.”

Senku always said that. Chrome shook his head. “I wanted to, that’s all. I love you.”

“I love you too.” They shared more sweet kiss, lingering between them before Senku pulled away. “I guess that means I’m on dish duty, then.” He stacked up all the dishes on the tray and set it aside. Before he could carry it into the kitchen though, his phone buzzed with an incoming text message. He grabbed it off the charger and turned on the screen.

Chrome frowned when he saw a perturbed expression cross Senku’s face. “What is it?” he asked.

“We’ve been forcibly invited to go out tonight,” Senku explained. “Apparently Gen is hosting a party and he said we have to be there, he won’t take no for an answer.”

Chrome let out a tiny sigh of relief. He was worried it was something more serious—though for Senku, being forced to interact with a crowd _was_ serious. “Okay. We’ll go, we’ll make our appearances and say hi to everyone, and then we can leave. In and out in an hour or less.”

Senku’s lips quirked up into a tiny smile. “I love you so much, Chrome.”

“I love you too, Senku!”

The party wasn’t actually all that bad once they got there. It was being held at Gen’s spacious home, and all of their college friends were there—plus a few others, like Senku’s old mentor Dr. Xeno and his husband Stanley. “Glad you could finally join us, Senku-chan, Chrome-chan!” Gen said with a wide grin as he handed them both drinks. It smelled like a foul concoction of who-knew-what in a red plastic cup that had to have been imported from the US. Glancing over at each other, Senku and Chrome both shrugged and downed the beverages.

“Shit, that’s _baaad,”_ Chrome muttered. “Is that nital or something?”

“It’s my proprietary blend of fine liquors and fruit juices,” Gen said. “I see your palate must not be refined enough to enjoy the subtleties.”

“Maybe not, but I’m pretty sure another one of those would cause internal bleeding,” Senku replied with a chuckle. “Thanks for having us over, Gen. We have an early day tomorrow but we can hang out for a little while, at least.”

Gen gave them both a pointed look, but shrugged. “Suit yourself. Just make sure to have _un-fay!”_ He smirked and wandered off to talk to someone else.

Senku rolled his eyes and turned to Chrome. “Come on, let’s make the rounds.”

With a nod, Chrome followed Senku as they wandered the lower floor of the house. The majority of people were in the living room or out on the _engawa_ on the back of the house, enjoying the late summer weather. Food and drinks were plentiful; laughter, even more so. After a while, with the help of their earlier drinks, Senku and Chrome found themselves relaxing on the polished wooden patio with their bare toes brushing the grass of the backyard.

“Hey, you two.” Chrome glanced up to see one of Senku’s old friends approaching. Senku had known Shishio Tsukasa since middle school, though they had a two year age gap. He’d also attended the same university as Senku and Chrome, and had run around in similar social circles. Tsukasa sat down on the other side of Senku, leaning in and brushing their shoulders together. “I heard from Gen you were out here. Hiding from everyone else?”

“Kohaku and Mozu just went back inside to get something to eat,” Chrome explained. “We decided to stay out here. It’s too nice to go back inside.”

“That’s true. It is beautiful out. The last time I remember getting to enjoy a night like this was… what, three years ago? Senku, it was that night you and I went to the beach together.”

Chrome couldn’t help frowning. Three years ago… he and Senku hadn’t gotten together yet at that point. Chrome had been broken up with Ruri for nearly a year, but it hadn’t been until Christmas that Senku had confessed.

Wait… did Senku and Tsukasa have a thing going on back then? Looking at Senku’s face, Chrome could see a faint blush to his cheeks as Tsukasa went on about this beach trip they’d been on together.

“Chrome, I’ll be right back.” Senku’s voice cut through Chrome’s wandering thoughts.

“Okay…” He watched as Senku stood and made his way back into the house. When he turned his gaze back on Tsukasa, the older man had a secret little smile on his face, as if there was something he knew about that Chrome didn’t.

Chrome didn’t like it.

“So, you and Senku have been friends for a while, huh?” It was actually his first time being able to speak with Tsukasa privately like this. Part of him wanted to hear stories about high school age Senku from Tsukasa, since they’d been friends back then.

Tsukasa nodded. “Yes, I suppose that’s one way of putting it. We’ve been close for a long time.” 

“When did you first meet?”

“We were schoolmates in middle school, actually. He was in first year, and I was in third year. I helped him and Taiju build a rocket.”

Chrome nodded; but something about the way Tsukasa spoke made him think there was more to the story than just Tsukasa helping Senku with his rocket. “And what happened between the two of you in high school? You’re such good friends, I can’t imagine that it was all you two had done together.”

Tsukasa chuckled softly. “You could say that. High school was a little different from middle school. Our relationship was… tumultuous, at best. I think more often than not we found ourselves rivals.”

“Oh… I see.” 

Nodding, Tsukasa explained, “We were only in school together for one year, but we both had our… cliques, I suppose you could call them. We clashed on a few occasions. But then I graduated and life moved on. We reconnected when Senku started at Hirosue, both older and wiser, and we ended up rekindling our friendship.”

That all tracked with what Senku had told him. “Well, I’m glad you two were able to be friends again! I know Senku always thought very highly of you.”

“I wonder…” The cryptic response drew a head tilt from Chrome and a curious look. Tsukasa just chuckled and shook his head. “Oh, it’s nothing. Just… during those first two years, before you and he got together, we were more than just friends.”

 _We were more than just friends._ The words seemed to echo oddly in Chrome’s ears. What did that mean? What kind of relationship did Senku have with Tsukasa? But he’d said Chrome was his first real boyfriend…

“I’m back,” Senku called out, approaching the two men and plopping down between them. Chrome couldn’t help watching Senku like a hawk, looking to see if there was some subtle hint, some hidden sign that might help him understand what Tsukasa had just said.

Tsukasa stood at that point and put a hand on Senku’s shoulder. “Well, I’ll leave you two be, then. It was nice seeing you both.” 

Chrome couldn’t tell what he was doing exactly, but there was a subtle flex to his forearm that made it look like he was squeezing Senku’s shoulder… and then Senku sagged the slightest bit, eyes fluttering, before he straightened up and flailed his arm in the older man’s general direction. With a laugh, Tsukasa took a step back to avoid the flailing hand. “Yeah, yeah. Go punch a lion or something, will ya?” Senku muttered.

“Of course, Senku. Have a good night.” He gave them both a nod before meeting Chrome’s eyes and giving a slight smile—one that Chrome didn’t like the look of one bit.

Once Tsukasa was gone, Senku looked over at Chrome. “You about ready to go?”

Chrome nodded in agreement. “Yeah, sounds good. Let’s get out of here before we’re force-fed any more nasty boozy drinks.” The two men headed toward the front of the house to say their good-byes and get their shoes, retreating from the party under the light of the full moon.

 _We were more than just friends._ Chrome couldn’t get Tsukasa’s words out of his mind. Should he ask Senku about it? He wouldn’t do it now, obviously; he’d wait until they got home. But… did it really involve him? After all, they hadn’t started dating until well into their third year at university. So whatever Senku did the first two years was his own business. 

The only thing he could think of was that they were in a physical relationship. Senku had told him before that using a toy or his hand felt no different to him than _being fucked by another person._ He would only know that if he had experience. At the time, Chrome had assumed maybe Senku had been talking about some one-night stands… but maybe he and Tsukasa had been in some kind of… physical relationship.

A whole bevy of mental images appeared in Chrome’s mind. Senku was so small and delicate compared to Tsukasa—he’d just seen proof of that a few moments ago, when one of Tsukasa’s hands had completely engulfed Senku’s shoulder. It would probably be easy for the taller man to pick up Senku and manhandle him, pushing him over furniture or even outright holding him in place while fucking into him…

Chrome had to bite his lip and swallow heavily as his cock began to stir in his pants.

He cursed mentally. Why was he getting turned on by the idea of someone else having Senku? There had to be something wrong with him, something not right in the head.

But… he’d thought the same thing when he’d started feeling his heart beat faster and butterflies in his stomach around Senku, hadn’t he? And that had turned out to be a completely normal thing once he did research.

Maybe he needed to get on the computer tonight and do some digging. Surely he would be able to find some answers, and then he could talk to Senku armed with better information. If he didn’t, Senku would likely tell him to do research anyway—this way he was already one step ahead.

Luckily tomorrow was Sunday and he didn’t have work, so if he stayed up late, it wouldn’t cause any problems. 


	2. Chapter 2

**Summary for the Chapter:**

> Chrome does some research. When he tries to talk to Senku the first time, it doesn't exactly go well... but giving up is not in Chrome's nature.

Senku had already long since passed out—he couldn’t hold his liquor well, and it tended to make him sleepy, so he’d dozed off against Chrome’s shoulder on the train ride home. Thankfully Chrome had been able to get him to wake up enough to carry his own weight back to their apartment, even if he’d been half-asleep and reliant on Chrome to guide him.

But Senku falling asleep so early had a silver lining: it left Chrome plenty of privacy to do his research. Making sure he was in a private tab with his VPN turned on, Chrome typed  _ “aroused by hearing about partner having sex with other person”  _ into the search bar and hit enter—and, just like that fateful day three years before, he had a whole new world opened up to him. Not of sexuality, but of  _ sex, kink, safe word, humiliation, submissive,  _ **_cuckolding._ **

Some of this stuff Chrome already knew about. He and Senku were pretty adventurous—they had blindfolds and handcuffs and, obviously, plenty of toys. Chrome had even been considering the idea of having Senku top him, though the first time he’d brought it up Senku had quickly changed the subject. 

But  _ Dom/sub  _ and  _ cuck _ and  _ stud _ were new to him… and Chrome’s cheeks burned with both humiliation and arousal as he took himself to hand after completing his research. Just the mental image of Tsukasa sweeping Senku off his feet right in front of Chrome, pulling him into a demanding kiss with obvious tongue, and Chrome not being able to do a damned thing about it—that alone was enough to make him spill over his fingers with a gasp. 

He cleaned himself up quickly and disposed of the tissues deep in the bathroom trash can. Then, still feeling a little guilty about the whole thing, he tucked himself into bed next to Senku and curled up next to the smaller man in the hopes that sleep would make him feel better in the morning.

He woke up to the smell of hot coffee wafting under his nose. When he opened his eyes, Senku was in bed next to him, holding a cup of his own. “I thought you might need this as much as I did,” he murmured. “Aspirin is on the bedside table, too.”

As always, Senku was right. He had woken up with a massive headache. “Thank you, Senku.” He rolled over and swallowed two pills dry, then washed them down with the coffee. “So what do you want to do today? You have the day off from work too, right?”

Senku nodded. “Yeah. We need to go grocery shopping and do some cleaning… but after that, maybe we can watch a movie together after dinner.”

“I like that idea! We haven’t gotten to do that in a while.” Chrome smiled and leaned over, pressing a kiss to Senku’s cheek. Senku turned his head and returned the kiss with one of his own; turning into two, and three, and soon the two were lying on the bed in a leisurely makeout session, with Senku halfway on top of Chrome.

When they broke for air, Senku murmured, “Hnn… what’s gotten into you, Chrome? You’re normally not so… needy.”

Chrome’s eyes were a little hazy from the kiss and his heart pounded as the memories from before came back to his mind, unbidden. “I… Senku, is there anything I can do to make you feel better? You know, in bed?”

Senku’s brows furrowed. “What’s all this about? You know I love when we do things together, Chrome. I’m happy with everything.” He pulled back and Chrome leaned up on one elbow. 

“I know, I just… Tsukasa mentioned last night that the two of you used to…  _ be _ together, and I—” Chrome’s words trailed off when he saw the look on Senku’s face. Stormy, perturbed, almost  _ angry _ for some reason. “What’s wrong?”

“Tsukasa shouldn’t have been running his mouth,” Senku muttered. The irritation was clear in his voice. “We had nothing together. It was strictly physical. But more than that, why do you care? You’ve never been the jealous type.”

“I— I don’t  _ care, _ Senku, I’m not upset that you and Tsukasa did that… I just…” 

Senku shook his head, pushing himself up and off the mattress. “I’m going to go clean the bathroom. You do the kitchen, alright?”

Chrome frowned as Senku fled the room. That… wasn’t how he’d wanted that conversation to go at all.

Senku seemed to be content to avoid Chrome for the rest of the morning. Their conversation weighed heavily on his mind as he wiped down the countertops and mopped the kitchen floor. Was Senku more upset with Tsukasa for spilling the beans, or with Chrome for bringing it up? He’d told Senku he wasn’t upset; and he wasn’t, not really. 

Or, at least,  _ upset _ wasn’t the word for it. He was more confused than anything, because of what he’d learned the night before. Chrome was still trying to wrap his head around the concept. Was it the idea of being humiliated that had him aroused? He didn’t think that was the case, because most of the time when someone talked down to him, it only made him want to prove them wrong even more.

But then again… he already knew from personal experience that he couldn’t satisfy Senku. Not the way Tsukasa had in the past, at least. It wouldn’t surprise Chrome if Tsukasa was the one Senku thought about on those nights when he couldn’t go more than one round. Tsukasa probably had enough stamina that he could fuck until morning…

And wasn’t  _ that _ a stimulating mental image? Chrome would never be able to deny that Tsukasa was a handsome man. He and Senku looked good together, too. They had that air about them, like their destinies were intertwined or something… maybe they had been lovers in another life.

Chrome sighed as he hung up the mop and moved toward the washing machine to do laundry. He was just going around in circles again. And honestly, it didn’t matter in the end  _ why _ Tsukasa fucking Senku aroused him—because he had no intention of breaking up with Senku.

By the evening, Senku must have cooled off, because he walked out onto the balcony while Chrome was pulling down the laundry he had hung out to dry earlier in the day. Leaning out over the edge of the railing to look down at the city below, he murmured, “Tsukasa’s and my…  _ thing, _ it was all just stress relief.” 

“I understand that,” Chrome replied quietly. He folded the last of Senku’s work shirts, then moved over to water their potted plants. “I want to reiterate, I’m not mad or upset. I just…”

“Is this some kind of machismo thing? You feel like you aren’t as much of a man as Tsukasa?”

“No! Stop putting words in my mouth and let me think.”

“...Sorry.” Chrome looked back at Senku, seeing how he had his arms crossed over his chest in an almost sheepish gesture. 

With a sigh, he stepped closer to press a kiss to Senku’s forehead. “That last one was a little closer. I just… I don’t know what I’m feeling right now, I’m struggling to find the words to explain it. But I love you, and I don’t want this to ruin our relationship.”

“If you’re struggling to find the words, then use words until you get there,” Senku murmured. “I find it’s ten billion percent easier to figure out what I’m trying to say if I just start talking.”

“Mm… fair. Alright. But let’s go inside and discuss this over dinner.”

Senku nodded in agreement. “Sounds good. Ramen?”

“You read my mind.” Chrome smiled gently and squeezed Senku’s hand.

An hour or so later, they sat down with their meal and drinks. “Okay, we have dinner,” Senku said. “Now let’s talk. Start from the beginning.”

Chrome sucked in a deep breath and let it out in a rush. “Alright. So. I do have to admit that, at one point, when our relationship was new, I  _ was _ a little jealous of your friendship with Tsukasa. But last night, while you were gone, he and I were talking. He told me some of the history the two of you had, and in his words, the two of you were  _ more than friends _ those first two years of university.”

Senku’s mouth curled into a grimace, but he didn’t speak, so Chrome continued. “Honestly, I thought I would be jealous, like, insanely so. And I was, but something about the thought of you and Tsukasa doing that… I don’t know. It just… it made me feel things I’ve never felt before. Like, it made me upset, but also… kind of ridiculously horny.” 

Chrome sighed and took a bite of his sandwich, if only to give himself a break to gather his thoughts once more. Once he’d swallowed, he added, “So, I did what I always do: I researched. Last night, I looked it up and I found out about cucking.”

“Oh, Chrome, please don’t tell me you’re buying into that whole 'beta cuck' thing.”

Cheeks flaming in embarrassment, Chrome shot back, “No! Not that kind of cuck.  _ Cuckolding _ , it’s a sexual fetish thing. It’s… well, it’s being aroused by watching someone have sex with your partner and… and the person is kind of holding it over you that they’re better at pleasuring your partner than you can.”

Senku’s eyes widened. And if there was one thing Chrome knew beyond the shadow of a doubt, it was that surprising Senku with new information was incredibly difficult—but apparently he hadn’t known about cuckolding. “What… what are you trying to say, Chrome?” Senku asked.

“I’m not saying anything. I just want you to think about this. If you’re not interested, then I’ll never bring it up again. We can go about our lives just as they were before. But… if you  _ do _ decide you want to try it… just let me know.”

Senku didn’t respond immediately. “Take your time,” Chrome urged him. “It doesn’t have to be tonight. Hell, it doesn’t have to be this  _ week. _ Just, whenever you’re ready.” Standing up from the table, Chrome picked up his empty plate to carry it into the kitchen. He dropped a kiss to the crown of Senku’s head, mashing down his spiked up cowlicks in the process before they sprang back into place. “I love you.”

“I love you too,” Senku murmured. He stayed at the table for a long time, sipping at his tea; his food pushed by the wayside as he turned over Chrome’s words in his mind.


	3. Chapter 3

**Summary for the Chapter:**

> Senku dreams about reconnecting with Tsukasa and thinks about Chrome's request.

_The first emotion Senku felt when seeing Tsukasa at his university was_ **_relief_** _. Finally, he wouldn’t be alone! He had someone he knew in the sea of rank strangers. “Tsukasa!” he called out. “What are you doing here? I thought you were going off to live in America for your MMA career.”_

_Tsukasa looked up and glanced around in surprise before his eyes fell upon Senku. The expression on his lips morphed from surprise into secretive delight as he grinned. “Senku, it’s great to see you again. I didn’t realize you had decided to attend this university.”_

_The two of them were surrounded by young adults close to Senku’s age; and yet, with the way they looked at each other, one would be hard pressed to make either of them acknowledge the rest of them. As far as Senku was concerned, all of it was nothing but background noise. “Yeah. My old man wanted me to attend Hirosue since he teaches there, but I told him I wanted to try to get into T University… and here I am. What about you, though?” He’d already asked, but since Tsukasa hadn’t answered, he tried again._

_“I went to America for a little over a year,” Tsukasa explained, “and took classes through T University online. But my little sister woke up last October and I rushed back to Japan. While she’s in rehabilitation, I’m attending classes in person.”_

_“Mirai woke up? That’s great news. I’m really happy for you, Tsukasa.” The poor girl had been in a coma since she was six, caused by the car wreck that had taken their parents’ lives as well. That had been over seven years ago, when Senku was 11 and Tsukasa was 13. He’d been forced to move in with an uncle while he finished middle school, and all of his and Mirai’s inheritance had gone into paying her medical expenses to keep her alive. By the time he had graduated middle school, he’d started working part time to help make ends meet._

_That had been around the time he’d discovered mixed martial arts; and before long, he had become known as the Strongest Primate High-Schooler. He had been in third year with a whole posse of followers by the time Senku had made it up to high school. Of course they had liked picking on the nerdy kid, even if his best friend Taiju had stood in his place to take his beatings. The end of the school year had resulted in something of a “stone war” between the two sides that had only ended with Tsukasa’s graduation._

_And now, here they were—at the same school once more. Except this time, there was no posse; no one but the two of them._

_“So. Can we go back to being friends, or are we going to fight for the rest of our lives?” Senku asked, crossing his arms over his chest._

_“I’d love nothing more than for us to get back to the way we were in middle school,” Tsukasa replied. A soft smile crossed his lips._

_Lips quirking up to a grin, Senku nodded and held out his fist. “Me too.” Tsukasa returned the fist-bump, cementing their bond._

_The more they spent time together, the more Senku found himself noticing things about Tsukasa that he’d thought he’d long since buried—the cut of his jaw, the strength of his chest, the swell of his… well. Needless to say, Senku wasn’t one millimeter interested in a_ ** _relationship,_** _per se, but he found himself jerking off more frequently as the pressure of his advanced classes mounted. It was one of the few things that could take the edge off enough to let him sleep._

_When Tsukasa mentioned the dark circles growing under his eyes, Senku confessed his issue. “Oh, is that what’s going on? You should find a girlfriend or something, then,” Tsukasa suggested._

_“No way. I don’t have time for a relationship. And I’m not one millimeter interested in women, anyway.”_

_“A boyfriend, then?”_

_“Again, no time for a relationship.”_

_“Then a sex friend.” At Senku’s uncertain expression, Tsukasa continued, “It’s something I learned about in America. They call them ‘friends with benefits.’ No dates, no commitments; just meeting up and having sex when it’s convenient. You get more satisfaction than you do from just dealing with things yourself.”_

_“And you’re bringing this up, why?”_

_“Because if you want someone to do it with, I wouldn’t mind. We can help each other out.”_

_The idea was ten billion percent ludicrous; but at the same time, the idea of having someone other than himself bringing him pleasure sounded… enticing. Especially if it meant not spending hours just trying to satisfy himself enough to sleep._

_“Alright. Let’s try it.”_

* * *

Waking up the next morning was… awkward for Senku, especially after the events of the day before and then dreaming about his and Tsukasa’s past before Senku had met Chrome. He hurried out of bed to the toilet to hide his morning wood from Chrome’s wandering hands—he already felt guilty, and letting Chrome get him off first thing in the morning would only make him feel worse. 

Chrome packed lunch boxes for both of them, making a quick chicken and vegetable stir fry. Loading up two boxes with the food and plenty of rice, he handed one of them to Senku on his way out the door; Senku replied with a peck and a quick wave. “I’ll see you after work,” he called out.

“Have a good day,” Chrome replied. He smiled as he returned the kiss, seemingly back to normal after last night’s conversation. That was good, right? He was glad that Chrome wasn’t too upset by his lack of response. 

The commute to work was as busy as usual. Senku had gotten a job with JAXA after college, in honor of his late father. Byakuya’s dream had always been to be an astronaut; but Senku, thin and frail as he was, focused more on the _literal rocket science_ and became an engineer for the Japanese space agency. They were a few weeks away from their next rocket launch, which was being done in partnership with NASA in the United States, as well as China and Russia’s national space agencies. The rocket would send supplies to the eight astronauts currently housed in the International Space Station. There were three astronauts from Russia, two from the US, two from China, and one from Japan orbiting the planet at millions of miles per hour and performing all types of research. 

Senku normally found himself completely absorbed in his work, but he couldn’t stop running over the conversation from the night before in his mind. Chrome wanted to watch someone else have sex with him? Presumably it was Tsukasa, given the context of the situation—but did it matter who it was, in the end? Well, _obviously,_ ten billion percent so. It was rare enough for Senku to even be interested in having sex with anyone at all. Even his… _relationship,_ if he could call it that, with Tsukasa in college had been solely an agreement for mutually beneficial stress relief.

… Hadn’t it?

Senku’s eidetic memory served him well when it came to remembering obscure facts and blowing the competition out of the water when JAXA employees went to the local izakaya for trivia night. But having a perfect memory didn’t make him a mind reader. He could remember how he experienced the conversation between himself and Tsukasa where he’d ended their agreement, but he couldn’t begin to fathom what might have been going through Tsukasa’s head at the time. 

Was it possible that Tsukasa had fallen in love with Senku? His first instinct was to scoff and say _no, what would make someone like Tsukasa fall in love with someone like him?_ But then Chrome’s voice came to mind from the day he had confessed.

_“Senku, I… I really admire you, both your mind and your, um… your body. I think you’re beautiful, but you’re incredibly smart and talented and I just—please accept my feelings!”_

If Chrome were there to witness his self-doubt and self-deprecation, Senku knew he wouldn’t hesitate to slap some sense into him. A small smile quirked the corner of his lip at the thought. _“Are you looking down on me for being in love with you, asshole? Because I won’t stand for anyone talking about my boyfriend that way, not even you!”_

So maybe there was some truth to that thought… The look on Tsukasa’s eyes the night he had broken things off might have been more hurt than Senku had originally realized.

He needed to talk logistics with Chrome, but the idea of trying things with Tsukasa _was_ starting to grow on Senku. If nothing else, it would feel good.

“You look happy, Ishigami. Something on your mind?” one of Senku’s co-workers asked him.

Senku shook his head. “Nothing really. Just thinking about having dinner with my partner tonight.”

“Oh. Well, I hope you have fun, then!”

“Thanks. I think we will.” 

**Author's Note:**

> Feel free to join the Dr. Stone shipping server! All ships are welcome!  
> We have lots of events scheduled, RP our fave ships, share headcanons, etc!  
> [Click here to join us!](https://discord.gg/K7CzXYS)


End file.
